Added documentation about project hooks to README
Added documentation about project hooks to README

Since pre and post are deprecated and have been replaced by project hooks, the README should reflect this.
tmuxinator/tmuxinator,adamstrickland/tmuxinator,tmuxinator/tmuxinator,J3RN/tmuxinator,ethagnawl/tmuxinator,adamstrickland/tmuxinator,tmuxinator/tmuxinator,adamstrickland/tmuxinator,J3RN/tmuxinator,J3RN/tmuxinator,ethagnawl/tmuxinator,ethagnawl/tmuxinator